# ---
# title: 1332. Remove Palindromic Subsequences
# id: problem1332
# author: Tian Jun
# date: 2020-10-31
# difficulty: Easy
# categories: String
# link: <https://leetcode.com/problems/remove-palindromic-subsequences/description/>
# hidden: true
# ---
# 
# Given a string `s` consisting only of letters `'a'` and `'b'`. In a single
# step you can remove one palindromic **subsequence**  from `s`.
# 
# Return the minimum number of steps to make the given string empty.
# 
# A string is a subsequence of a given string, if it is generated by deleting
# some characters of a given string without changing its order.
# 
# A string is called palindrome if is one that reads the same backward as well
# as forward.
# 
# 
# 
# **Example 1:**
# 
#     
#     
#     Input: s = "ababa"
#     Output: 1
#     Explanation: String is already palindrome
#     
# 
# **Example 2:**
# 
#     
#     
#     Input: s = "abb"
#     Output: 2
#     Explanation: " **a** bb" -> " **bb** " -> "". 
#     Remove palindromic subsequence "a" then "bb".
#     
# 
# **Example 3:**
# 
#     
#     
#     Input: s = "baabb"
#     Output: 2
#     Explanation: " **baa** b **b** " -> "b" -> "". 
#     Remove palindromic subsequence "baab" then "b".
#     
# 
# **Example 4:**
# 
#     
#     
#     Input: s = ""
#     Output: 0
#     
# 
# 
# 
# **Constraints:**
# 
#   * `0 <= s.length <= 1000`
#   * `s` only consists of letters 'a' and 'b'
# 
# 
## @lc code=start
using LeetCode

## add your code here:
## @lc code=end
